Synthesis of oxide nanoparticles in low pressure flames

A method is described for the production of oxide nanopowders by controlled thermochemical decomposition of metalorganic precursor/carrier gas mixtures in low pressure flames. A specially designed burner is used to achieve a flat flame, extending a few millimeters out of the burner, which ensures that the temperature distribution and gas phase residence time are identical over the entire burner surface. Metalorganic precursors introduced along with the fuel/air mixture, therefore. experience completely uniform decomposition, thereby yielding a uniform nanopowder product. The substantial heat release in the flame allows the burner to support a high precursor flow rare. In this paper, we describe the progress made in flame synthesis of nanophase SiO2 (from Hexamethyldisilazane), TiO2 (Titanium ethoxide) and Al2O3 (Aluminum tri-sec butoxide) powders. (C) 1999 Acta Metallurgica Inc.